A band D Energy Performance Certificate is the most common rating for older homes in England, and a large share of London's privately rented stock sits in band D. If your rental property is rated D, you can let it today. The question landlords are asking is what happens next, and whether it is worth improving the rating before they have to. This guide explains what a D rating means, where the rules stand and which improvements usually move a London property from D to C.
What an EPC rating of D actually means
EPC ratings run from A, the most efficient, to G, the least. The band comes from a SAP score between 1 and 100 or more, calculated from the way the property is built, insulated, heated and lit. Band D covers SAP scores of 55 to 68. Band C starts at 69, so a property at the top of band D may only be a few points away from C, while one at 55 has further to go.
The score is based on standard assumptions about how a home is used, not on your actual bills. Two identical flats with different tenants will have the same rating. It reflects the building and its systems: the walls, roof, floors, windows, boiler, heating controls, hot water and lighting.
The certificate also shows a potential rating and a list of recommended improvements with an indication of their effect. That page is the best starting point for planning work, because it shows what the assessor thought would make the biggest difference for that property.
Can I still let a band D property?
Yes. Under the Minimum Energy Efficiency Standard, privately rented homes in England and Wales must have an EPC of at least band E, unless a valid exemption is registered. A band D property meets the current standard. Letting a property rated F or G without a registered exemption can lead to a civil penalty of up to £5,000 per property.
You must also have a valid EPC to market a property for rent and give a copy to the tenant at the start of the tenancy. An EPC is valid for ten years, so check the date on yours. A certificate from before improvements were made will understate the property.
The proposed move to band C
The government has proposed raising the minimum standard for privately rented homes in England and Wales to band C by 2030, alongside changes to how EPCs are calculated and presented. The details, including the timetable, any spending cap and the exemptions, have been the subject of consultation, so check the latest government guidance before planning work around a particular date.
Whatever the final rules, many landlords are choosing to act early. Improvements made between tenancies cause less disruption, a better rating helps a property let, and efficient homes are cheaper for tenants to heat, which reduces arrears and complaints about condensation and mould. Our EPC C by 2030 page sets out how we help landlords plan for it.
Why London properties are so often band D
Solid brick walls
Most London houses built before about 1930 have solid brick walls with no cavity to fill. They lose heat faster than cavity walls, and insulating them means internal or external wall insulation, which is more disruptive and is often restricted in conservation areas.
Converted flats
Flats in converted houses often have no loft of their own to insulate, shared walls and roofs controlled by the freeholder, and older electric or gas heating. The improvements available depend on what the lease allows.
Older heating and hot water
An older non-condensing boiler, basic controls or an uninsulated hot water cylinder can hold a property in band D on their own. These are often the quickest points to gain.
Improvements that usually move a D to a C
Every property is different, so treat this as a list to discuss with an assessor rather than a guarantee. The improvements below are the ones that most often make the difference in London homes:
- Loft insulation: topping up thin loft insulation is one of the most cost-effective measures where there is a loft to insulate. See our insulation page.
- Heating system and controls: a modern condensing boiler with a programmer, room thermostat and thermostatic radiator valves can make a large difference to the score.
- Hot water: insulating the cylinder and pipework, or removing an old cylinder when a combination boiler is fitted.
- Cavity wall insulation: for later properties with unfilled cavities, usually a straightforward improvement.
- Solid wall insulation: internal insulation on the coldest walls, where it is practical and permitted.
- Windows and doors: replacing single glazing with double glazing, subject to planning in conservation areas. See replacement windows and doors.
- Low energy lighting: a small gain, but cheap and quick.
- Renewables: solar panels or a heat pump can lift a rating significantly where the property suits them.
- Floor insulation: under suspended timber ground floors, often done when floors are up for other works.
Improving insulation and airtightness should go hand in hand with good ventilation. Sealing up an old house without extract fans in the kitchen and bathroom can cause condensation, which is why we check ventilation as part of any damp and mould or efficiency work.
A step-by-step plan for landlords
- Check your current certificate. Find the score, not just the band, and read the recommendations page.
- Get advice on the property. An assessor can tell you which measures would lift that particular property over 69.
- Prioritise. Start with the measures that gain the most points for the least disruption, and plan bigger works for the next void.
- Check consents. Conservation areas, listed buildings and leases can restrict windows, external insulation and alterations.
- Carry out the work. Keep invoices and product details, which the assessor will need.
- Get a new EPC. The certificate only changes when a new assessment is lodged.
Exemptions and special cases
The current rules allow landlords to register an exemption in certain situations, for example where all relevant improvements have been made and the property still falls short, or where required consent has been refused. Exemptions must be registered on the government's PRS Exemptions Register and last for a limited period. The exemptions under any new band C standard may be different, so do not assume today's exemptions will apply.
Some listed buildings and properties in conservation areas are harder to improve. Speak to the local authority before altering windows or external walls on these properties.
How the EPC assessment works
A domestic EPC for an existing home is produced by an accredited energy assessor using a reduced version of the government's SAP methodology. The assessor visits, measures the property and records the age and construction of the walls, roof and floors, the thickness of any loft insulation, the type of glazing, the boiler or heating system and its controls, the hot water arrangements, the lighting and any renewable technology. Where something cannot be seen, the software assumes a default based on the age of the building, which is often worse than reality.
That is why evidence matters. Invoices for cavity wall insulation, photos of insulation under floors, a boiler commissioning certificate or details of new windows allow the assessor to record what is really there rather than relying on defaults. Before a reassessment, gather the paperwork for every improvement made since the last certificate. On some properties that alone moves the score.
Selling or remortgaging a band D home
The minimum standard applies to letting, not selling, so you can sell a band D property and a buyer can live in it. A valid EPC is still required when the property is marketed. Some lenders now offer better terms on more efficient homes, and buyers increasingly look at the rating and the running costs it implies. If you are planning to sell a rented property with tenants in place, the buyer will be looking at the same band C question you are, so a clear plan or completed improvements can help the sale.
How GMAS can help
We arrange EPC assessments across London, carry out the improvement work through one point of contact, and arrange a new EPC once the work is finished. For landlords with several properties, we can plan improvements around voids and combine them with gas safety and electrical checks. See our landlord hub or call 07498 597339.
Frequently asked questions
Is an EPC rating of D good or bad?
Band D is about average for older housing in England. It meets the current minimum standard for letting, but it is below the band C level the government has proposed for rented homes.
Can I rent out a property with an EPC rating of D?
Yes. The current minimum for privately rented homes in England and Wales is band E, so a band D property can be let.
How many points do I need to get from D to C?
Band C starts at a SAP score of 69. Check the score on your certificate; a property near the top of band D may need only one or two improvements.
Do I need a new EPC after improvements?
Yes, if you want the rating to reflect the work. The existing certificate stays valid until it expires, but it will show the property as it was when assessed.
What is the cheapest way to improve an EPC rating?
It depends on the property, but loft insulation where there is a loft, better heating controls, cylinder insulation and low energy lighting are often the least expensive measures. The recommendations on your certificate are the best guide.